Nano Particle Metallic Paste Lid Attachment for IC Packages
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Solution Overview
Problem
Integrated Circuit (IC) device packages face challenges in reducing stress on thermal interface materials and lid attachment surfaces, particularly in lower temperature environments, which can lead to thermal mismatch issues and mechanical stress on IC devices and components.
Innovation Solution
The use of a nano particle metallic paste to connect the lid-ridge to the IC device carrier, forming a metallic connection that reduces stress and enhances thermal interface material efficiency, while also allowing for a contiguous underfill material instance between the IC device and the carrier, and between the lid-ridge and the carrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional lid attachment methods are used in lower temperature environments, then the lid can be connected to the IC device package, but thermal mismatch issues and mechanical stress on IC devices and components occur
Solution Approach 1:
The patent changes the material parameters of the attachment method by using nano particle metallic paste instead of traditional solder or adhesive. This material parameter change enables effective thermal conduction and stress distribution in lower temperature environments, resolving the thermal mismatch issue while maintaining reliable lid attachment.
Solution Approach 2:
The patent employs a composite material system consisting of nano particle metallic paste that combines the properties of metal particles for thermal conduction with a paste matrix for adhesion. This composite approach simultaneously addresses thermal mismatch and mechanical stress problems in low-temperature attachment scenarios.
2Stress or pressure
If the lid is positioned close to the IC device, then stress on thermal interface material is reduced and lid facing surface area is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent introduces a lid-ridge structure that segments the lid assembly, creating a carrier-facing surface that can be positioned close to the IC device without requiring complex overall package restructuring. This segmentation allows the critical thermal interface area to be optimized while keeping the rest of the package manageable.
Solution Approach 2:
The lid-ridge acts as an intermediary element between the lid and the IC device carrier. It provides a dedicated carrier-facing surface that mediates the thermal and mechanical interface, enabling close positioning and reduced stress without proportionally increasing manufacturing complexity.
3Reliability
If nano particle metallic paste is used for lid attachment, then thermal interface efficiency is enhanced and mechanical stress is reduced, but manufacturing process complexity increases
Solution Approach 1:
The patent applies the nano particle metallic paste to the lid-ridge carrier-facing surface in advance, before final assembly. This preliminary application allows for proper material distribution and preparation, simplifying the subsequent sintering and attachment processes while achieving enhanced thermal interface efficiency and reduced mechanical stress.
Solution Approach 2:
The patent replaces traditional mechanical attachment methods (such as soldering or adhesive bonding) with a sintering process for the nano particle metallic paste. This substitution eliminates complex mechanical fastening steps while providing superior thermal conduction and stress distribution, ultimately simplifying the overall manufacturing process despite the specialized sintering requirement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively reduces mechanical and thermal stress on IC devices and components, improving the reliability and performance of IC device packages by enhancing the thermal interface and mechanical bonding between the lid, carrier, and IC devices, even in lower temperature environments.
Implementation Method 1
sintering the first nano particle metallic paste to form a first metallic connection between the lower contact and the first pad
Implementation Method 2
The underfill is attached to a bottom surface of the IC device and to the upper surface of the IC device carrier and attached to the carrier facing surface of the lid-ridge bar and to the upper surface of the IC device carrier
Data Source
AI summary
An IC device package includes a carrier, one or more IC devices and a lid. The lid includes a lid-ridge. The lid is connected to the carrier by connecting the lid-ridge to the carrier with first nano particle metallic paste, prior to connecting the IC device to the carrier. Subsequent to connecting the IC device to the carrier, the lid is connected to the lid-ridge with second nano particle metallic paste. The nano particle metallic paste may be sintered to form a metallic connection. In multi-IC device packages, the lid-ridge may be positioned between the lid and the carrier and between the IC devices.